Cost today, gas VS diesel?

oldtanker

Well-known Member
This, today could be an interesting subject. With the modern diesel actually burning cleaner than a gas engine the emission's argument is out the window so anyone who supports gas because of emissions has no argument.

HP ratings: if the gas and diesel engine and both produce the same HP and torque one will not out pull the other. HP is HP, don't care if it's gas. diesel or steam. The same goes for torque.

So it boils down to cost to run and maintenance.

With EFI and EI there isn't much maintenance to do on a gasser other than oil and filters. On cars and trucks some have tune up intervals of 100,000K with 7,500 miles oil changes. If they still built 100HP tractors in gas you wouldn't really have any more maintenance to do over the diesel. Think of it, the modern gas engine is good for 200,000 miles or more. In that 200,000 miles there is one tune up (why do the 2nd if yer only going to run it 200,000). The one down side to gas would be engine life. While diesels can run 10,000 hours or more a gasser would, at todays build standards run about 1/2 that. But gas engines are generally under 1/2 the rebuild cost of a diesel.

A gas engine to diesel upgrade for a new pickup is about 8500 bucks. Id' bet the gas tractor would not have the same disparity at first because diesel today is the norm and the gasser would be to odd one. So the next consideration would be fuel consumption. Most of your older tractors around 100HP that were available in both fuels the gasser would burn about a gallon an hour more than the diesel. Back then diesel was about 2/3rds the cost of gas. So the only advantage of gas was initial purchase price. Today, diesel is higher than gas plus due to computers, injection and IE gas engine are more efficient. Back in the day the gas engine in general was about 60% efficient compared to about 80% for a non-turbo diesel. Today the gas engine is bumping that same 80% mark. So the big question is how 2 identical tractors at say 100HP, 1 gas and 1 diesel would compare today in fuel consumption. Would the diesel still be cheaper to run over 10,000 compared to the gasser?

Rick
 
In pickups. The entire long block gasser engine is cheaper to
replace than just injectors in a partly worn out emissions
diesel.
As for engine life in a pickup. My old 2003 has approx
160,00 miles and 4600hrs on the clock. Doesn't burn oil and
still has full power. Gas or diesel engine in that chassis. The
frame and body will be rusted away before either engine wears
out.
300,000 miles on an emissions gasser is common these
days.
Odd how so many of these die hard diesel lovers are stuck
in 1986. And quote numbers from that era.
 
Have a friend who had a 2003 Duramax--early model. Those early Duramaxs had a lot of problems and he experienced them all so he traded before it was worn out for a Chevrolet with gasser and the big motor to get the same or close size. Now he wishes he still had the Duramax. Gasser will climg Sidling Hill pulling a 38' 5th wheel at 50 the Diesel went up it at whatever speed he wanted and the gasser is eating twice the fuel doing it.
To top it off diesel fuel is almost the same price as premium.
 
Where the heck are you getting figures of any
engine - gas or diesel - with 80% efficiency?
That's a dream. Some of the most fuel efficient
gas engines are reaching 35% and the best diesels
around 45%.

If a farm tractor company today was offering a
gas engine, I don't know what the price difference
would be (as compared to diesel. During the 70s
and 80s, many auto companies were using converted
gas engines for diesels and the price difference
was lower. That includes the Isuzu 1.8 and 2.2,
Ford-IH 7.3, VW 1.6, GM 350, etc. Tractor
companies in the 60s and 70s were also making
"same engine formats" in gas or diesel. If done
now- I don't know what would be used? I suspect
rather then retool, the engines today would be
totally different.

I suspect that if the best technology was used on
a gas tractor today and used here in New York
where gas is $3.75 and diesel is $4.35 - fuel cost
versus work done would be near the same with
diesel winning a bit.

The Oliver 1800 gas tractor made in 1960 held the
world's record for fuel efficiency in a gas
tractor. Made 74 horsepower at 13.2 horsepower-
hours-per-gallon. Mainly due to using high
compression that was usually taboo in a farm
tractor. That 1800 gasser had the same or better
efficiency rating at max power then many diesels
at that time including the Farmall 706, Allis
Chalmers D19, Ford 6000, Deere 3020, etc.

Diesel fuel has more energy per pound as a fuel
But diesel compression-ignition is less efficient
then spark ignition in a gas engine IF compression
ratios are the same. So far, there are no working
gas engines with CR ratios like 18-1 like many
diesels are using. So, we'll see.
 
(quoted from post at 09:08:10 10/10/13) Have a friend who had a 2003 Duramax--early model. Those early Duramaxs had a lot of problems and he experienced them all so he traded before it was worn out for a Chevrolet with gasser and the big motor to get the same or close size. Now he wishes he still had the Duramax. Gasser will climg Sidling Hill pulling a 38' 5th wheel at 50 the Diesel went up it at whatever speed he wanted and the gasser is eating twice the fuel doing it.
To top it off diesel fuel is almost the same price as premium.

Dave, the question is, 2 engines both putting out the same HP and torque. Your friend isn't running that. The diesel was a 6.6 @ 300 HP and 520 FP torque and I think the biggest gasser offered by GM is the 6.0 at 300 HP and 360 FP of torque. If the gasser was putting out the 520 FP T then it would be a good comparison. They would also have to have about the same RPM range for a fair evaluation.

Rick

Rick
 
"Diesel fuel has more energy per pound as a fuel". Doesn't diesel fuel (the kind we use) contain about 19,300 btu per lb as opposed to gasoline which has about 20,300 btu per lb. State it the way we buy our fuels (by the gallon) and then diesel comes out ahead. Diesel=136,567 btu per gallon and gasoline=124,845 btu per gallon. I don't have a dog (or a cat) in this fight but your comment caught my eye. ;>)
 
I believe the diesel would be cheaper. Put 10 gals of gas in your tractor and park it for 3 or 4 weeks and if you are lucky it will have 5 or 6 gallons of good fuel left. Do the same with a diesel and you will still have the 10 gallons.
 
I've got a pair of Dodge 2500 4wd, QC auto's that I use in my business. One a Cummins, other a Hemi. Both bought in fall of 2003 (04 models) They both occasionally tow 14.000gvwr goosenecks with actual gross cargo weight around 8500lbs. The diesel now has just over 225,000 miles. Gasser is right at 215,000. Since new, I've kept very detailed service and operating expense records.

The gasser is BY FAR cheaper to operate, on top of being considerably less expensive initially. Granted there is SOME difference when hauling a heavy load, but not so much as to warrant the higher expense of owning/operating.

All things equal, I'd rather drive the gasser.

Both trucks will be replaced in the upcoming months. BOTH will be replaced with gassers.
 
In my neighborhood if you used gas in a tractor, less than that time you would have zero in it. Around here people are even starting to steal diesel and not always at night.
 
(quoted from post at 09:34:58 10/10/13) Where the heck are you getting figures of any
engine - gas or diesel - with 80% efficiency?
That's a dream. Some of the most fuel efficient
gas engines are reaching 35% and the best diesels
around 45%.

If a farm tractor company today was offering a
gas engine, I don't know what the price difference
would be (as compared to diesel. During the 70s
and 80s, many auto companies were using converted
gas engines for diesels and the price difference
was lower. That includes the Isuzu 1.8 and 2.2,
Ford-IH 7.3, VW 1.6, GM 350, etc. Tractor
companies in the 60s and 70s were also making
"same engine formats" in gas or diesel. If done
now- I don't know what would be used? I suspect
rather then retool, the engines today would be
totally different.

I suspect that if the best technology was used on
a gas tractor today and used here in New York
where gas is $3.75 and diesel is $4.35 - fuel cost
versus work done would be near the same with
diesel winning a bit.

The Oliver 1800 gas tractor made in 1960 held the
world's record for fuel efficiency in a gas
tractor. Made 74 horsepower at 13.2 horsepower-
hours-per-gallon. Mainly due to using high
compression that was usually taboo in a farm
tractor. That 1800 gasser had the same or better
efficiency rating at max power then many diesels
at that time including the Farmall 706, Allis
Chalmers D19, Ford 6000, Deere 3020, etc.

Diesel fuel has more energy per pound as a fuel
But diesel compression-ignition is less efficient
then spark ignition in a gas engine IF compression
ratios are the same. So far, there are no working
gas engines with CR ratios like 18-1 like many
diesels are using. So, we'll see.

JD you are right. I was using figures given to me years ago. I just looked it up and as far as thermo energy is concerned your numbers stand.

I'm just curious, if they built a long stroke low RPM gas engine using modern technology, that equaled a diesel, both HP and torque, in a tractor application if the new technology would make the gas or diesel cheaper to run over the normal lifetime of the tractor using current fuel prices. I think it's an interesting concept. But seeing as how no one is building a higher HP tractor in gas it's more of a question. I'm not arguing one way or the other. I just put it out there as a question.

Rick
 
I was sort of think along these same lines but wonder with LP so cheap it would be hard to beat.

Dust off the old LP tractors and put them back to work.
 
We learned that too - especially on pickups that are used for everything from towing to highway miles like a car - the maintence on gas trucks is about half that of diesels. And we've had Duramax's and Power Strokes - no one ever worked up the courage to buy a Dodge. We joked that everytime a gas goes in the shop its $600-$700, everytime a diesel goes in the shop its $2000-$3000.
 
You guys mentioned the 2 things I thought of immediately when I read the original post. Any time I kept gasoline on a farm I lost more to evaporation and theft than I burned in the tractor.
 
I agree with this guy. I always get told the diesel is cheaper to run but I disagree like you and would rather drive my hemi, and they will pull a trailer to.
 
LP isn't "cheap" in my neck of the woods (central NY). Not by the gallon an not by the lower MPGs it gets. Propane is $2.70 to $2.90 per gallon here. Gas is $3.75 and diesel $4.20-$4.30. That comes to one dollar buying 29,000 BTUs with propane, or 30,500 BTUs with gasoline or diesel fuel. They are all pretty close (kind of like it's intentional). Considering a diesel engine is the most efficient and the propane engine the least efficient - running propane makes no sense around here.

School buses around here wasted some money on propane and CNG. They get 9.5 MPG with propane, 10 MPG with CNG and 13.3 MPG with diesel.

I have noticed though that more and more big rig road-tractor fleets are running CNG instead of diesel. I assume because CNG is awful cheap in many areas.
 

Old tanker if one of the things you mean by "new technology" is direct injection then the compression ratio could be increased into diesel territory.Same displacement,same air induction system then power would be close.However if C/R is pushed that high the entire engine from head to crankshaft must be beefed up which would give you a gas engine that would weigh as much as a diesel.
 
Some of the high diesel compression ratio is just to get the engine started while cranking.
Some of the old engines such as the Lister LS series used high compression to start and low compression to run.
The direct injection gassers are into the 11 to 1 range now. That is near diesel.

Contrary to popular belief, high compression does not make power. It's the pressure difference between compression and combustion pressure where effective working pressure is derived.
600psi compression and 1100psi combustion does no more work than 200psi compression and 700psi combustion.
 
You are going to see direct injection gasoline engines get much better performance and economy than the current port injection engines. They still a spark plug to ignite, but are really high compression and rely on evaporative cooling to prevent pre ignition when the fuel is injected.

The lines are quite blurry now.
 
(quoted from post at 14:08:01 10/10/13) LP isn't "cheap" in my neck of the woods (central NY). Not by the gallon an not by the lower MPGs it gets. Propane is $2.70 to $2.90 per gallon here. Gas is $3.75 and diesel $4.20-$4.30. That comes to one dollar buying 29,000 BTUs with propane, or 30,500 BTUs with gasoline or diesel fuel. They are all pretty close (kind of like it's intentional). Considering a diesel engine is the most efficient and the propane engine the least efficient - running propane makes no sense around here.

School buses around here wasted some money on propane and CNG. They get 9.5 MPG with propane, 10 MPG with CNG and 13.3 MPG with diesel.

I have noticed though that more and more big rig road-tractor fleets are running CNG instead of diesel. I assume because CNG is awful cheap in many areas.

You stole my thunder JD! I was about to say I have a Cockshutt 30 propane, aftermarket, not OE. It's great on fuel for raking or hauling wagons, but start plowing or running the haybine where you have to run the RPMs up and she sucks the fuel right up. I have to say though, that old Buda engine is one smooth girl for a 4 cyl. Sweet running tractor. But LPG is not for power if you're paying $2.50 or more a gallon.

Something you and I and other NYer's have to remember is that each gallon of gas at the pump has 70 cents of tax added on, each gallon of diesel 75 cents! Farm diesel isn't as bad but it's still higher than gas last time I got any.

I'll tell you guys this much on gas vs diesel- running something like a brush hog with a 45 hp gas or 45 hp diesel the gas engine is going to suck down a lot more fuel.
 
i would like to know ware you can find a 100 hp gas that will only burn 1 gal per hour more than a 100hp diesel back in the day 1800 Oliver gas on full load would burn 12 to 14 gals per hour diesel 6to7 per hour it takes btus to make hp check the btu in gas and diesel these useage were about the same for Deere 4020 or 806 IH
 
After having gas trucks, then my 2000 ford with the 7.3 diesel,
I'd never go back to gas. But there runing the new diesels
today it looks like?? Mine had 190,000 on it, hope it will be
around awhile.
 

(reply to post at 17:00:03 10/10/13)

So I guess you are claiming that the Nebraska Test Institute fabricated their test results and Oliver never got the world's record for fuel efficiency in a gas tractor?

I admit I do not own a test lab, or an Oliver 1800 gasser. I DO believe the test results. The Oliver gas tractor run at the max of 74 horsepower used 5.6 gallons of gas per hour (if you believe those lying b*stards at the Nebraska Test place). Making 64 horsepower, the Oliver used 4.9 gallons of gas per hour. At 32.4 horse it used 3.4 gallons of gas per hour.

The Deere 3020 diesel making 64 horsepower used 5.1 gallons of diesel fuel per hour. Making 29 horsepower it used 3 gallons of diesel per hour.

The Farmall 806 took 7th place for the gas tractor world record in 1963. It made 93 horsepower and used 7.4 gallon of gas per hour. Compare that to a Farmall 966 diesel that made 91 horse using 7.1 gallons of diesel fuel.

mvphoto21369.jpg
 
(quoted from post at 01:00:03 10/11/13) .... 1800 Oliver gas on full load would burn 12 to 14 gals per hour diesel 6to7 per hour it takes btus to make hp check the btu in gas and diesel these useage were about the same for Deere 4020 or 806 IH

Hogwash. I spent many hours in the seat of an Oliver 1800 series A gasser back in the day. (Still my alltime favorite tractor to work ground even over our newer and bigger 1066 IH diesel that came along later.). Never ever did it burn 12 to 14 gallons in an hour. Nebraska tests reports are very accurate on this tractor. That said a series B or series C Oliver 1800will not be as fuel efficient as a Series A but even the later series would not come anywhere close to your figures.

The tractor was very fuel efficient (for a gasser) and had incredible power for only 74 hp. Ours was not babied either as it usually drew all the oversize implements to pull as the other wore out diesels (MM G705) would not handle them. Even pulled 5-16" plows with it in scrub hard to plow ground. Of course the nice 1066 eventually came along and that became our big horse.
 
Lol a train isnt diesel powered all the diesel motor does is run a generator and the train is electric power. The diesel motor dont pull the cars electric motors do.
 
(quoted from post at 14:08:01 10/10/13) LP isn't "cheap" in my neck of the woods (central NY). Not by the gallon an not by the lower MPGs it gets. Propane is $2.70 to $2.90 per gallon here. Gas is $3.75 and diesel $4.20-$4.30. That comes to one dollar buying 29,000 BTUs with propane, or 30,500 BTUs with gasoline or diesel fuel. They are all pretty close (kind of like it's intentional). Considering a diesel engine is the most efficient and the propane engine the least efficient - running propane makes no sense around here.

School buses around here wasted some money on propane and CNG. They get 9.5 MPG with propane, 10 MPG with CNG and 13.3 MPG with diesel.

I have noticed though that more and more big rig road-tractor fleets are running CNG instead of diesel. I assume because CNG is awful cheap in many areas.

WOW! I just filled my tank from 20% to full at 1.59 2 days ago. At 2.50 to 2.70 I'd put in a wood stove.

Rick
 
(quoted from post at 19:28:32 10/10/13)
WOW! I just filled my tank from 20% to full at 1.59 2 days ago. At 2.50 to 2.70 I'd put in a wood stove.

Rick

Propane is not even close to "cheap" up here. I see people in other areas quoting real low prices like you are and it boggles my mind. I haven't paid under $2.00 in years. I have paid over $3.00 though, not in bulk, but still!

The folks that are really going to hurt this winter are the fuel oil burners. Our church is spending close to $800.00 to switch to a propane burner. They figure it will pay for itself in cost savings in the first 2 months running it! $4.00 plus a gallon for fuel. It would probably be cheaper to get a bulk load of tractor diesel, hand pump it into 55 gallon drums and then hand pump it into some old guys fuel oil tank. They won't deliver tractor fuel to a residence and put it in your tank, so I assume taxes make up a large part of the cost.
 
I'm in north central Ohio. I just paid $ 1.69 for LP and that was not a large quanity as I only have a 300 gal. tank.
The begining of this year it was the same.
This is the lowest price I have paid since I moved to my place in 1998-1999. Shortly after this the price went up pretty good.
I do have to add 6.75% sales tax which Ohio now increased this so it should be 7% now for my county.
 
(quoted from post at 04:21:42 10/11/13)
(quoted from post at 19:28:32 10/10/13)
WOW! I just filled my tank from 20% to full at 1.59 2 days ago. At 2.50 to 2.70 I'd put in a wood stove.

Rick

Propane is not even close to "cheap" up here. I see people in other areas quoting real low prices like you are and it boggles my mind. I haven't paid under $2.00 in years. I have paid over $3.00 though, not in bulk, but still!

The folks that are really going to hurt this winter are the fuel oil burners. Our church is spending close to $800.00 to switch to a propane burner. They figure it will pay for itself in cost savings in the first 2 months running it! $4.00 plus a gallon for fuel. It would probably be cheaper to get a bulk load of tractor diesel, hand pump it into 55 gallon drums and then hand pump it into some old guys fuel oil tank. They won't deliver tractor fuel to a residence and put it in your tank, so I assume taxes make up a large part of the cost.


Bret, taxes out there must be killing you guys. I thought it was bad a couple of years ago when we were at the 2.50 mark. I should of had them fill the tank in Aug. It was 1.39 then.

Rick
 
You must be a bit slow in picking up on the topic and facts.
It"s already been discussed and facts stated about the difference in HD continuous service vs light duty intermittent service .
Don"t you get it yet?
Marine propulsion/power, utility leaking power, ploughing the back 40, railroad, off road trucks and highway heavy trucks. That is HD.
You or Bubba on the highway with or without your boat trailer is light duty service. Mowing your lawn once a week is light duty too.
 
A typical DI diesel today runs a 16.5 to 1 or 17.5 to 1 "mechanical compression ratio" and when under turbo boost the "actual" compression ratio gets higher due to more air per volume.

Many of the IDIs from the 70s to the 90s were running 21.5 to 1 mechanical compression ratios.

I don't know of any gas engines getting close to that. We had many back in the 60s and 70s with 11 to 1, but they required good gas and usually were not long lived.
 
(quoted from post at 19:16:07 10/10/13) Lol a train isnt diesel powered all the diesel motor does is run a generator and the train is electric power. The diesel motor dont pull the cars electric motors do.

So you think the generator that is driven by a deisel engine in a locomotive spins over real easy when under heavy load.Guess again!Even the alternator in your car sucks up HP when under load.
 
(quoted from post at 08:56:19 10/11/13) A typical DI diesel today runs a 16.5 to 1 or 17.5 to 1 "mechanical compression ratio" and when under turbo boost the "actual" compression ratio gets higher due to more air per volume.

Many of the IDIs from the 70s to the 90s were running 21.5 to 1 mechanical compression ratios.

I don't know of any gas engines getting close to that. We had many back in the 60s and 70s with 11 to 1, but they required good gas and usually were not long lived.

Thank you,JDmaris.
 
iirc part of the reason for diesel compression ratio dropping since emissions were introduced. Was to reduce combustion chamber temperature and NOX production.
Intercooling the intake air and using EGR coolers are also used to reduce combustion chamber temps.
 
Generators don't turn that hard, a little 5hp generator will run
quiet a bit and that's only 5hp
 
(quoted from post at 13:39:43 10/11/13) Generators don't turn that hard, a little 5hp generator will run
quiet a bit and that's only 5hp

And how much of a load will that "little 5hp generator" pull? Why do you think those diesel electric locomotives have 16 cylinder engines stuffed in them? Ain't no SBC gonna turn those monster generators!
 
A gas would run it to. If you wanna get technical a electric
motor will outpower them all.
 
The truth is that there is no free lunch.
A Diesel Electric locomotive is powered by Diesel fuel. Its efficiency is degraded by the generator and motors (with about 80% efficiency each). The Diesel would have higher fuel efficiency if it was connected to the wheels with a gear set, instead of the Gen/Motor set. But there is the issue of getting the massive power (6000HP (Diesel)in a General Electric Dash-9 CW44) to a movable set of wheels. An automatic would do it but they have mediocre efficiency as well. The energy to move the freight comes from good old Diesel oil the compromise is made to use a generator and motors to allow dynamic braking (retarder system with massive resistors to dissipate the heat) and smooth starts. With respect, Jim
 
i said 100hp not 74 if you go to 1800 .b or c models you get close to 4020 or 806.i worked for oliver Dealer back in 1964 he sent 1800b out to farmer to try out they put it on a 2 row chopper it drank fuel 12 gals per the farmer did not by it
 
Well an 1800 series B is only 80 PTO so a whopping 6 more hp than the series A. That said the hydropower did rob some fuel efficiency but still no way that tractor would drink 12 -13 gallon per hour. Maybe turn the choke off next time.

1800 series A (5.6 gallon per hour by Nebraska test at max load). Again I have spent many hours in the seat of one of these and almost always overloaded.

1800 series B (6.6 gallon per hour under max load at Nebraska test). Admittingly never ran a series B.

I think you are totally getting confused with the different figure 13.18 hp/hrs/gallon which is a totally different measurement ratio that measures efficiency and the higher this number the better. Many Early diesels did not meet this efficiency but later ones did and exceeded it.

A similar in size 85 PTO hp Case 970 diesel for example would be (5.48 gallons per hour at max load) (efficiency 15.64 hp/hrs/gallon).

A similar in size 85 PTO hp Case 970 gasoline (8.02 gallon per hour at max load) (efficiency 10.34 hp/hrs/gallon).

For the record: I am not arguing gasoline is superior to diesel. Diesel is almost always far superior. That said there were some decent gassers that got decent fuel economy and they can be suitable for some applications. I would like to see what a modern gasser with modern technology could achieve fuel economy wise in a gasser tractor.
 
I would agree that diesel pickups ruled from the introduction of the Cummins 6BT until the last mechanical pump ISB in 2002.
The the price of diesel fuel vs. gasoline and the EPA's rules ruined a good thing.
 
Here is a really good chart showing the savings of diesel compared to its gas counterpart. So, Powerstroke vs Triton, Cummins vs Hemi, Duramax vs Vortec, etc. http://www.hitchanything.com/towing-fuel-economy-infographic.html
 
(quoted from post at 14:26:33 12/26/13) Here is a really good chart showing the savings of diesel compared to its gas counterpart. So, Powerstroke vs Triton, Cummins vs Hemi, Duramax vs Vortec, etc. http://www.hitchanything.com/towing-fuel-economy-infographic.html

Looks like the port injected gassers don't have cost disadvantages vs. the 2007 and later EPA diesels. The DI gassers will be cheaper to operate than the diesels.
I do in some ways still wish for a pre common rail ISB Cummins in a GMC chassis with diesel costing 3/4 the price of gasoline like it should.
 

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